1. 14-day centralized quarantine + 7-day home quarantine + 7-day home health monitoring, nucleic acid testing, and "point-to-point" closed-loop transfer measures are implemented for people arriving in Shaanxi Province whose destinations are in the province;
2. In the medium- and high-risk areas and their counties (cities, districts, flags), the implementation of centralized isolation and observation measures for 14 days (14 days of isolation from the time of departure from the above areas), during which four nucleic acid tests;
3. All the people returning to Shaanxi need to provide proof of a negative nucleic acid test within 48 hours.
The substance of nucleic acid test is the nucleic acid of the virus. Nucleic acid test is to look for the presence of nucleic acids of foreign invading viruses in the patient's respiratory specimens, blood or feces to determine whether or not they are infected by the new coronavirus. A "positive" nucleic acid test is proof that the virus is present in the patient's body.
The new coronavirus first reproduces in the respiratory system after it infects the human body, so it is possible to determine whether the human body is infected with the virus by detecting nucleic acids in sputum and nasopharyngeal swabs. A positive nucleic acid test can be used as a new standard for confirming a new coronavirus infection.
A "false-positive" nucleic acid test means that the patient was not infected with the new coronavirus but had a positive nucleic acid test result. This "false positive" is usually due to cross-contamination between specimens during laboratory testing or contamination of the nucleic acid in the laboratory. Technically, false positives can be avoided as long as quality control is strictly implemented in the laboratory.
False-negative nucleic acid testing means that the patient's clinical symptoms, lung imaging, and even epidemiologic history all support a new case of pneumonia, but the patient's nucleic acid test results are "negative," and the test results are not consistent with the clinical picture.
The usual reasons for "false negatives" are:
1. In the early stages of viral invasion, the amount of virus in the body has not yet reached a detectable level. In the incubation period of the virus, mild symptoms, severe symptoms of different periods, different parts of the human body (such as nasopharyngeal, oropharyngeal, trachea, bronchial and alveolar) there will be differences in the viral load. Therefore, different sampling timing and sampling sites may lead to the collection of specimens without a sufficient amount of virus;
2. Any test reagent has its lower limit of detection (i.e., sensitivity), and if the virus in the patient's specimen fails to reach the lower limit of detection of the reagent used, a false-negative test will occur;
3. The performance of the laboratory instrumentation and equipment and the personnel of the detection of poor performance, poor implementation of quality management may also produce a "false-negative" result. The lack of implementation of quality management can also produce "false negatives".
Legal basis
The Chinese People's **** and the State Law on Prevention and Control of Infectious Diseases
Article XII In the Chinese People's **** and the State field of all units and individuals must accept disease prevention and control agencies, medical institutions related to infectious diseases, such as investigation, testing, collection of samples, isolation and treatment and other preventive, control measures, and to provide truthful information thereon. Disease prevention and control institutions, medical institutions shall not disclose relevant information involving personal privacy, information.